CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income (loss)	$ (1,028)	$ (3,687)	$ 7
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	61	26	10
Impairment of long-lived assets	45	0	0
Provision for credit losses	36	78	59
Share-based compensation	654	1,572	24
Change in fair value of convertible notes and warrant liability	0	2,045	0
Other	35	(1)	2
Changes in operating assets and liabilities:
Segregated securities under federal and other regulations	0	135	(135)
Receivables from brokers, dealers, and clearing organizations	12	36	(104)
Receivables from users, net	3,386	(3,362)	(2,772)
Securities borrowed	(517)	0	0
Deposits with clearing organizations	142	(102)	(103)
Current and non-current prepaid expenses	33	(135)	0
Other current and non-current assets	(26)	(54)	(46)
Accounts payable and accrued expenses	(62)	134	67
Payables to users	(1,775)	578	3,532
Securities loaned	(1,817)	1,730	1,247
Other current and non-current liabilities	(31)	122	88
Net cash provided by (used in) operating activities	(852)	(885)	1,876
Investing activities:
Purchase of property, software, and equipment	(28)	(63)	(24)
Capitalization of internally developed software	(29)	(20)	(8)
Acquisitions of a business, net of cash acquired	0	(125)	0
Purchase of investments	(25)	(27)	0
Sales of investments	42	0	0
Other	(20)	(3)	0
Net cash used in investing activities	(60)	(238)	(32)
Financing activities:
Proceeds from issuance of common stock in connection with initial public offering, net of offering costs	0	2,052	0
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	16	7	0
Taxes paid related to net share settlement of equity awards	(12)	(422)	0
Proceeds from issuance of convertible notes and warrants	0	3,552	0
Draws on credit facilities	21	1,968	938
Repayments on credit facilities	(21)	(1,968)	(938)
Payments of debt issuance costs	(10)	0	0
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	0	0	1,267
Proceeds from exercise of stock options, net of repurchases	6	14	9
Net cash provided by financing activities	0	5,203	1,276
Effect of foreign exchange rate changes on cash and cash equivalents	(1)	0	0
Net increase (decrease) in cash, cash equivalents, segregated cash and restricted cash	(913)	4,080	3,120
Cash, cash equivalents, segregated cash and restricted cash, beginning of the period	10,270	6,190	3,070
Cash, cash equivalents, segregated cash and restricted cash, end of the period	9,357	10,270	6,190
Cash and cash equivalents, end of the period	6,339	6,253	1,403
Segregated cash, end of the period	2,995	3,992	4,780
Restricted cash (current and non-current), end of the period	23	25	7
Cash, cash equivalents, segregated cash and restricted cash, end of the period	9,357	10,270	6,190
Supplemental disclosures:
Cash paid for interest	12	12	3
Cash paid for income taxes, net of refund received	$ 4	$ 6	$ 6